A greylag goose is a large goose native to Europe and Western Asia. This type of goose is thought to be the primary ancestor of most domestic geese breeds. The greylag goose is grey-brown on its back, with grey plumage on its neck and a white underbelly. Its scientific name is Anser anser, and it is part of the large family Anatidae that includes geese, ducks, and swans. An alternate spelling used predominantly in the United States is "graylag."
The habitat of the greylag goose includes the US, Western Siberia, Asia, parts of China, Iceland, the British Isles, and Northern and Southern Europe. In the United States, there are both wild and domestic flocks, though the birds native range is restricted to Asia and Europe.
This type of goose is a migratory bird that moves south and to the west in the winter. In mild climates, such as the British Isles, there are wild flocks that stay year-round. The "lag" portion of the name greylag goose is derived from its habit of being one of the last of the migratory geese to move south in the winter.
Greylag geese have a wingspread of about 30 to 35 inches (76 to 89 cm) and are about 31 inches (80 cm) inches long. Mature birds weigh 6 to 8 pounds (about 2.7 to 3.6 kg), and males are often larger than females. The greylag generally is considered the largest of the Anser anser species.
Greylag geese are herbivores and granivores, feeding on shoots, pond plants, roots, tubers, nuts, fruits and grains. This type of goose also favors domestic crops, such as potatoes, carrots, and turnips. These geese can often be found grazing across fields.
The greylag goose builds shallow nests on the ground in marshy areas among reeds, in hollow areas, at the base of trees, and in the underbrush. The nests are built out of reeds, brush, and other plant materials. The greylag goose tends to build nests in wetlands, around ponds and lakes and on small islands.
The females lay between three and 12 pale white eggs in the spring, with an incubation time that ranges from 27 to 29 days. Once out of the egg, the goslings are taken care of and taught to feed themselves by the parents for about eight weeks. After eight weeks, young greylag geese are independent. The birds are relatively solitary during the breeding season, with nests scattered around an area usually at least 36 feet apart. In the late summer and early fall when the birds are molting and preparing for migration, large flocks of up to 25,000 birds come together.